import java.util.Scanner;

/**
 * Created with IDEA
 * author:ju bai
 * Date:2021/5/7
 * Time:16:30
 **/
public class Main1 {

    /**
     * 1
     * <p>
     * 1  1  1
     * <p>
     * 1  2  3  2  1
     * <p>
     * 1  3  6  7  6  3  1
     * <p>
     * 1  4  10 16 19  16 10  4  1
     * 每日一题-杨辉三角的变形
     *
     * @param args
     */
    public static void main1(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int n = sc.nextInt();
            if (n <= 2) {
                System.out.println("-1");
            } else if (n % 2 == 1) {
                System.out.println("2");
            } else if (n % 4 == 0) {
                System.out.println("3");
            } else {
                System.out.println("4");
            }
        }
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int n = sc.nextInt();
            int m = 2 * n - 1;
            int[][] a = new int[n][m];
            //初始化
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                    a[i][j] = 0;

                }
            }
            a[0][0] = 1;
            for (int i = 1; i < n; i++) {
                a[i][0] = a[i][2 * i] = 1;
                for (int j = 1; j < 2 * i; j++) {
                    if (j == 1) {
                        a[i][j] = a[i - 1][j] + a[i - 1][j - 1];
                    } else {
                        a[i][j] = a[i - 1][j] + a[i - 1][j - 1] + a[i - 1][j - 2];
                    }
                }
            }
            int k = 0;
            for (; k < m; k++) {
                if (a[n - 1][k] % 2 == 0) {
                    System.out.println(k + 1);
                    break;
                }
            }
            if (k == m) {
                System.out.println(-1);
            }
        }
    }
}
